Background: The intraoperative epidural analgesia (EA) has the potential to reduce stress response to surgical trauma which induces a transient immunoactivation that has a negative impact on the outcome. This study investigates the effect of intraoperative EA versus intravenous analgesia (IA) on the immune function.
Methods: A total of 35 consecutive patients candidated to undergo major surgery for colon cancer were randomly assigned to intraoperative EA (n = 18) or IA (n = 17). Blood samples for TNF-α, IFN-γ, IL-1, IL-2, IL-4, IL-6, IL-10, IL-12, and GM-CSF were obtained before surgery (T(pre)), 3 h (T(3h)), and 24 h (T(24h)) after skin incision. Data on postoperative complications were prospectively collected and analyzed.
Results: In the EA group, IL-4 increased from T(pre) to T(3h) and from T(3h) to T(24h), IL-10 increased from T(pre) to T(3h) and persisted unmodified thereafter. At all time-points, IL-4 and IL-10 serum levels were significantly higher than those in the IA group. Conversely, in the IA group, IL-4 and IL-10 serum levels did not change while all other cytokines levels were significantly higher compared with the EA group. In particular, IL-6 progressively reached a 7-fold increase of its basal value at T(24h). Complications were significantly more common in IA patients (13 of 17) compared with EA patients (7 of 18) (P = .024).
Conclusions: Our results indicate that in cancer patients undergoing major elective colon surgery, the EA attenuates the surgery-induced proinflammatory response and the typical postoperative transient immunosuppression and seems associated with a reduced rate of postoperative complications compared with IA.